SU901931A1

SU901931A1 - Device for measuring generator frequency-modulated signal alternation rate and instability

Info

Publication number: SU901931A1
Application number: SU802937098A
Authority: SU
Inventors: Владимир Иванович Гомозов; Николай Гаврилович Батурин; Николай Иосифович Прокопюк; Борис Васильевич Струков
Priority date: 1980-06-04
Filing date: 1980-06-04
Publication date: 1982-01-30

Description

Устройство относится к радиоизмерениям.The device relates to radio measurements.

Известно устройство для измерения средней скорости изменения частоты и линейности модуляционных характеристик частотно-модулированных генера- ^!торов, которое содержит генераторы, линию задержки, смесители,, делитель частоты, фазовращатель с аттенюатором, интегратор, фильтр нижних частот , переключатели , осциллографический индикатор, электронно-счетный частотомер, частотные детекторы, умножители и управитель частоты [1).A device for measuring the average rate of change of frequency and linearity of the modulation characteristics of frequency-modulated oscillators is known ^! torus, which contains generators, a delay line, mixers, a frequency divider, a phase shifter with an attenuator, an integrator, a low-pass filter, switches, an oscillographic indicator, an electronically counted frequency meter, frequency detectors, multipliers and a frequency controller [1).

Недостаток устройства - его сложность. ¹ The disadvantage of this device is its complexity. ¹

Наиболее близким по технической сущности к предлагаемому является устройство, содержащее усилитель промежуточной частоты, смеситель, уси- ₂литель промежуточной частоты, частотный детектор, смеситель, лампу бегущей волны (ЛБВ) , фазовращатель с аттенюатором, генератор, гетеродин,The closest in technical essence to the proposed is a device comprising an intermediate frequency amplifier, mixer, ₂ usi- divisor intermediate frequency, a frequency detector, a mixer, a traveling wave tube (TWT), a phase shifter with an attenuator, a generator, a local oscillator,

ЧАСТОТЫ ЧАСТ0ТН0СИГНАЛА ГЕНЕРАТОРА интегратор, линию задержки, делитель частоты,электронно-счетный частотомер, управитель частоты, видеоусилитель, генератор пилообразного напряжения, усилитель сигнала ошибки, фильтр нижних частот, индикатор. При этом выход делителя частоты подключен ко входам синхронизации генератора пилообразного напряжения и индикатора. Выход генератора через последовательно соединенные линию задержки, лампу бегущей волны, смеситель, усилитель, смеситель, усилитель, частотный детектор, интегратор, фильтр нижних частот, усилитель, управитель частоты и гетеродин подключены ко входам делителя частоты, электронно-счетного частотомера и второму входу смесителя. Выход генератора подключен к первому аноду лампы бегущей волны непосредственно, а к спирали - через фазовращатель с аттенюатором. Кроме того, выход интегратора подключен через видеоусилитель ко второму входу осцил лографического индикатора, а второй выход проверяемого генератора соединен со вторым входом смесителя 121.FREQUENCY OF THE FREQUENCY OF THE GENERATOR SIGNAL integrator, delay line, frequency divider, electronic counting frequency meter, frequency control, video amplifier, sawtooth generator, error signal amplifier, low-pass filter, indicator. In this case, the output of the frequency divider is connected to the synchronization inputs of the sawtooth generator and indicator. The output of the generator through a series-connected delay line, a traveling wave lamp, a mixer, an amplifier, a mixer, an amplifier, a frequency detector, an integrator, a low-pass filter, an amplifier, a frequency controller, and a local oscillator are connected to the inputs of the frequency divider, electron-counted frequency meter, and the second input of the mixer. The generator output is connected directly to the first anode of the traveling wave lamp, and to the spiral through a phase shifter with an attenuator. In addition, the integrator output is connected via a video amplifier to the second input of the oscillographic indicator, and the second output of the tested generator is connected to the second input of the mixer 121.

Устройство не обеспечивает достаточной точности измерений. 5The device does not provide sufficient measurement accuracy. 5

Цель изобретения - повышение точности измерений.The purpose of the invention is improving the accuracy of measurements.

Поставленная цель достигается тем, что в устройство для измерения скорости изменения и нестабильности час- 10 тоты частотно-модулированного сигнала генератора, содержащее первый усилитель промежуточной частоты, первый смеситель, один вход которого подключен к выходу гетеродина, а выход через 5 последовательно включенные второй усилитель промежуточной частоты и частотный детектор подключен к входу интегратора, второй смеситель, один вход которого соединен с выходом про- 20 веряемого генератора, а второй вход второго смесителя соединен с выходом лампы бегущей волны, один вход которой через линию задержки соединен с выходом проверяемого генератора, а вто-; рой вход соединен с ее третьим входом через фазовращатель, индикатор, вход которого подключен к выходу первого усилителя, причем вход управления гетеродина через последовательно 30 включенные управитель частотой и второй усилитель подключен к выходу фильтра нижних частот, введены режекторный фильтр, ограничитель, второй фильтр нижних частот, переключатель, пиковый ₃₅детектор, второй частотный детектор и измеритель, вход которого через второй частотный детектор соединен с выходом гетеродина и вторым входом лампы бегущей волны, причем выход перво- ₄₀го смесителя через второй фильтр нижних частот и первый контакт переключателя соединен с входом первого из упомянутых усилителей, а выход интегратора через второй контакт переключателя _4Jсоединен со входом пикового детектора, выход которого подключен ко входу фильтра нижних частот, при этом режекторный фильтр включен между выходом второго смесителя и входом первого ₅₀усилителя промежуточной частоты, а ограничитель включен между выходом первого усилителя промежуточной частоты и вторым входом первого смесителя.This goal is achieved by the fact that in the device for measuring the rate of change and instability of the frequency-10 frequency of the frequency-modulated signal of the generator, containing the first amplifier of the intermediate frequency, the first mixer, one input of which is connected to the output of the local oscillator, and the output through 5 series-connected second amplifier of the intermediate the frequency and the frequency detector is connected to the input of the integrator, the second mixer, one input of which is connected to the output of the verified generator 20, and the second input of the second mixer is connected to Exit traveling wave tube, one input of which is coupled through a delay line to output the checked generator, and the second; A swarm input is connected to its third input through a phase shifter, an indicator, the input of which is connected to the output of the first amplifier, the control input of the local oscillator through a series-connected frequency controller and the second amplifier connected to the output of the low-pass filter, a notch filter, a limiter, and a second low-pass filter are introduced switch, a peak detector _35, frequency detector and a second meter input thereof via a second frequency detector coupled to the oscillator output and the second input of the traveling wave tube, and you Gross carrying od th mixer ₄₀ via a second low-pass filter and a first switch contact is coupled to an input of said first amplifier and the output of the integrator via a second switch contact _4J connected to the input of the peak detector, the output of which is connected to the input of the lowpass filter, the notch filter is connected between the output of the second mixer and the input of the first ₅₀ intermediate frequency amplifier, and the limiter is connected between the output of the first intermediate frequency amplifier and the second input of the first mixer.

На чертеже приведена структурная электрическая схема предлагаемого устройства. .The drawing shows a structural electrical diagram of the proposed device. .

Устройство содержит усилители 1 и 2 промежуточной частоты, смесители 3 и 4, частотный детектор 5» лампу 6 бегущей волны (ЛБВ), фазовращатель 7, гетеродин 8, интегратор 9» линию 10 задержки, усилители 11 и 12, фильтры 13 и,14 нижних частот, пиковый, детектор 15, режекторный фильтр 16, ограничитель 17, индикатор 18, управитель 19 частотой гетеродина, частотный детектор 20, измеритель 21, переключатель 22. Индексом 23 обозначен проверяемый генератор.The device contains amplifiers 1 and 2 of intermediate frequency, mixers 3 and 4, frequency detector 5 ”lamp 6 traveling wave (TWT), phase shifter 7, local oscillator 8, integrator 9” line 10 delay, amplifiers 11 and 12, filters 13 and 14 lower frequency, peak, detector 15, notch filter 16, limiter 17, indicator 18, control unit 19 of the local oscillator frequency, frequency detector 20, meter 21, switch 22. Index 23 denotes the tested generator.

Работа устройства заключается в следующем.The operation of the device is as follows.

При измерении скорости частотной модуляции и линейности модуляционных характеристик ЧМ генераторов (отклонений частоты от линейного закона частотной модуляции) переключатель 22 находится в первом положении. Выходной линейно-частотно модулированный сигнал исследуемого генератора 23 поступает через линию 10 задержки с временем задержки на ЛБВ 6 с квадратурной амплитудно-фазовой модуляцией выходным гармоническим колебанием гетеродина 8. Номинальная частота колебаний гетеродина 8 F_ro выбирается с таким расчетом, чтобы она была значительно больше предполагаемых отклонений мгновенной частоты исследуемых сигналов от линейного закона изменения частоты во времени. Величина F_f0составляет десятки мегагерц. Величина запаздывания линии 10 задержки выбирается из условия обеспечения требуемого диапазона измеряемых величин и составляет десятые доли микросекунды. «When measuring the frequency of the frequency modulation and the linearity of the modulation characteristics of the FM generators (frequency deviations from the linear law of frequency modulation), the switch 22 is in the first position. The output linearly-frequency-modulated signal of the studied generator 23 enters through the delay line 10 with a delay time on TWT 6 with quadrature amplitude-phase modulation by the output harmonic oscillator oscillator 8. The nominal oscillator frequency 8 F _ro is chosen so that it is much higher than the expected deviations of the instantaneous frequency of the studied signals from the linear law of frequency change over time. The value of F _f0 is tens of megahertz. The delay value of the delay line 10 is selected from the conditions for ensuring the required range of measured values and is tenths of a microsecond. "

Задержанный сигнал, смещенный по частоте на величину F_r , перемножается в смесителе 4 с незадержанным сигналом исследуемого генератора 23· На выходе смесителя 4 образуются комбинационные составляющие разностной и (суммарной частоты, а также низкочастотная составляющая. Составляющая разностной частотыThe delayed signal shifted in frequency by the value of F _r is multiplied in mixer 4 with the unstoppable signal of the studied generator 23 · At the output of mixer 4, the combination components of the difference and (total frequency, as well as the low-frequency component) are formed.

Ър1= Fr+ Ht) выделяется усилителем 1. Низкочастотная составляющая обусловлена тем, что квадратурная амплитудно-фазовая модуляция не обеспечивает полного подавления несмещенной составляющей спектра выходного сигнала ЛБВ бив смесителе 4 происходит перемножение незадержанного и задержанного несме-t щенного сигнала. Она приводит к па5 раЗитной амплитудной модуляции полезной разностной составляющей, а следовательно, к снижению точности измерений. Для уменьшения паразитной амплитудной модуляции полезной составляю- 5 щей .сигнал на вход усилителя 1 подается через режекторный фильтр 16, который подавляет нежелательную низкочастотную составляющую. Полное устранение паразитной амплитудной моду- 10 ляции осуществляется ограничителем 17.Bp1 = Fr + Ht) is distinguished by amplifier 1. The low-frequency component is due to the fact that the quadrature amplitude-phase modulation does not completely suppress the unbiased spectrum component of the TWT output signal in mixer 4, and an undue and delayed unshifted signal is multiplied. It leads to parasitic amplitude modulation of the useful difference component, and, consequently, to a decrease in the measurement accuracy. To reduce spurious amplitude modulation of the useful component 5. The signal to the input of the amplifier 1 is fed through a notch filter 16, which suppresses the undesirable low-frequency component. Complete elimination of spurious amplitude modulation 10 is carried out by the limiter 17.

С выхода ограничителя 17 сигнал разностной частоты поступает на вход смесителя 3, на другой вход которого подается гармонический сигнал гетеро- 15 ди,на 8. Усилитель 2 выделяет сигнал второй промежуточной частоты ⁼ 2fr + ίΚ t).From the output of the limiter 17, the difference frequency signal is fed to the input of the mixer 3, to the other input of which a harmonic signal of hetero 15 diodes is supplied, by 8. Amplifier 2 selects the signal of the second intermediate frequency ⁼ 2fr + ίΚ t).

Сигнал с выхода усилителя 2 подается на вход частотного детектора 5, 20 переходная частота которого равна удвоенной номинальной частоте гетеродина⁰ 8 и составляет 2^₀.The signal from the output of amplifier 2 is fed to the input of the frequency detector 5, 20 whose transition frequency is equal to twice the nominal frequency of the local oscillator ⁰ 8 and is 2 ^ ₀ .

При отрицательном знаке скорости Частотной модуляции (-$) величина 25 второй промежуточной частоты F_n₽2 относительно частоты 2Гго уменьшается, а при положительном знаке скорости ^частотной модуляции (+J ) - увеличивается. При этом среднее за время зо длительности импульса значение смещения частоты сигнала на выходе усилителя 2 относительно 2F_ro однозначно определяет величину скорости частотной модуляции сигнала генератора 23· 35With a negative sign of the frequency modulation speed (- $), the value of 25 of the second intermediate frequency F _{n £} 2 relative to the frequency 2Ggo decreases, and with a positive sign of the speed ^ frequency modulation (+ J) it increases. In this case, the average over the time duration of the pulse duration value of the frequency offset of the signal at the output of amplifier 2 relative to 2F _ro uniquely determines the magnitude of the frequency modulation speed of the signal of the generator 23 · 35

Инерционная система АПЧ гетеродина 8, состоящая из смесителя 3, усилителя 2, частотного детектора 5, интегратора 9, пикового детектора 15, фильтра 13, усилителя 12 и управителя 19, а также частотный детектор 20 и измеритель 21 позволяют автоматизировать измерение величины и определение знака скорости частотной модуляции, а также одновременно расши- ⁴⁵рить диапазон измерения отклонений частоты от линейного закона частотной модуляции. Постоянная времени фильтра 13 выбирается значительно больше времени корреляции отклонений ⁵⁰от линейного закона частотной модуляции. Поэтому величина и знак усредненного смещения частоты сигнала на входе частотного детектора 5 относительно частоты 21ϊ·_ο, характеризующие ве- ⁵⁵личину и знак , отслеживаются гетеродином 8 и измеряются частотным детектором 20 с измерителем 21. Переход ная частота детектора 20 выбирается . равной 2fj₀, а измеритель 21 имеет нулевое значение на середине шкалы. Это обеспечивает непосредственное измерение скорости частотной модуляции с учетом ее знака. Внутриимпульсные же отклонения частоты от линейного закона (j(t) измеряются по индикатору, подключенному через переключатель 22 и усилитель 11 к выходу интегратора 9·The inertia system of the AFC of the local oscillator 8, consisting of a mixer 3, an amplifier 2, a frequency detector 5, an integrator 9, a peak detector 15, a filter 13, an amplifier 12, and a driver 19, as well as a frequency detector 20 and a meter 21, make it possible to automate the measurement of magnitude and determination of the sign of speed frequency modulation, and simultaneously expansion ⁴⁵ rit range measurement frequency deviation from linear frequency modulation. The time constant of the filter 13 is selected significantly more than the correlation time of deviations ⁵⁰ from the linear law of frequency modulation. Therefore, the magnitude and sign of the averaged frequency offset signal at the input of the frequency detector 5 with respect to frequency 21ϊ · _ο, characterizing of Great mask ⁵⁵ and the sign are tracked by the local oscillator 8 and frequency detector 20 are measured with a measuring instrument 21. The transition frequency a detector 20 is selected. equal to 2fj ₀ , and meter 21 has a zero value in the middle of the scale. This provides a direct measurement of the frequency modulation rate, taking into account its sign. The intra-pulse deviations of the frequency from the linear law (j (t) are measured by an indicator connected via switch 22 and amplifier 11 to the output of the integrator 9

Включение пикового детектора 15 обеспечивает устойчивость независимо от периода следования исследуемых радиоимпульсов и повышает точность измерения скорости частотной модуляции J за счет уменьшения ошибок системы в паузах между импульсами.The inclusion of the peak detector 15 provides stability regardless of the repetition period of the studied radio pulses and improves the accuracy of measuring the frequency modulation speed J by reducing system errors in the pauses between pulses.

При измерении нестабильностей частоты немодулированных сигналов переключатель 22 находится в другом положении. Выходной сигнал генератора 23 поступает на смеситель 4 и линию 10 задержки и после перемножения незадержанного и задержанного смещенного на частоту F_r сигналов в смесителе 4, как и в ранее рассмотренном случае, на его выходе образуется составляющая, разностной частоты (^р₄= ff-^zxF(t), rfleAF(t) - функция, описывающая в данном случае отклонения (флуктуации) частоты от ее среднего постоянного значения. Эта составляющая выделяется усилителем 1, усиливается и через ограничитель 17 поступает на вход смесителя 3· На другой вход смесителя 3 подается сигнал гетеродина 8 с частотой колебаний F_r . Так как частоты сигналов на обоих входах смесителя 3 одинаковы, то он работает в режиме фазового детектора, и его выходное напряжение пропорционально флуктуациям частоты исследуемого сигнала. Это напряжение выделяется фильтром 14 и через переключатель 22 и усилитель 11 подается на индикатор 18. Использование фазового детектирования позволяет повысить точность измерения флуктуаций частоты.When measuring frequency instabilities of unmodulated signals, switch 22 is in a different position. The output signal of the generator 23 is supplied to the mixer 4 and the delay line 10, and after multiplying the delayed and delayed signals shifted by the frequency F _r in the mixer 4, as in the previously considered case, a component of the difference frequency is formed at its output (^ p ₄ = ff- ^ zxF (t), rfleAF (t) is a function that describes in this case deviations (fluctuations) of the frequency from its average constant value.This component is extracted by amplifier 1, amplified, and fed through mixer 17 to the input of mixer 3 · To another input of mixer 3 get signal birthplace 8 at a frequency F _r oscillations. Since the frequency of signals on both inputs of the mixer 3 are the same, it operates in the phase detector, and its output voltage is proportional to the fluctuations of the frequency of the signal. This voltage is allocated a filter 14 and via switch 22 and the amplifier 11 is applied indicator 18. The use of phase detection can improve the accuracy of measuring frequency fluctuations.

Claims

(Sl) apparatus for measuring the rate of change and the frequency instability CHASTOTNOMODULIROVANNOGO SIGNAL GENERATOR apparatus relates to radioizmer audio m. A device for measuring the average rate of change of frequency and the linearity of the modulation characteristics of frequency modulated oscillators which soderh {um generators, delay line taps, , frequency divider, phase shifter with attenuator, integrator, low pass filter, switches, oscillographic indicator, electronic counting frequency meter, frequency components Ktorov by multiplying the frequency of Teli and ruler L11. The disadvantage of the device is its complexity. The closest in technical essence to the present invention is a device comprising an intermediate frequency amplifier, a mixer, an intermediate frequency amplifier, a frequency detector, a mixer, a traveling wave tube (, TWT), a phase shifter with an attenuator, a generator, a local oscillator. integrator, delay line, frequency divider, electron counting frequency meter, frequency manager, video amplifier, sawtooth generator, error signal amplifier, frequency filter, indicator. In this case, the output of the frequency divider is connected to the synchronization inputs of the sawtooth voltage generator and the indicator. The generator output is connected via a serially connected delay line, traveling-wave tube, mixer, amplifier, mixer, amplifier, frequency detector, integrator, low-pass filter, amplifier, frequency controller and local oscillator connected to the inputs of a frequency divider, an electron-counting frequency meter and a second input of the mixer. The output of the generator is connected to the first waveform of the traveling wave directly, and to the spiral through a phase shifter with an attenuator. In addition, the integrator output is connected via a video amplifier to the second input of the oscillation indicator, and the second output of the generator being tested is connected to the second input of the mixer 21. The device does not provide sufficient measurement accuracy. The purpose of the invention is to improve the measurement accuracy. The goal is achieved in that a device for measuring the rate of change and frequency instability of a frequency-modulated oscillator signal, containing the first intermediate frequency amplifier, the first mixer, one input of which is connected to the output of the local oscillator, and the output of the second intermediate frequency amplifier sequentially and frequency the detector is connected to the integrator input, the second mixer, one input of which is connected to the output of the generator being tested, and the second input of the second mixer is connected to you A traveling wave tube, one input of which is connected to the output of the generator under test through a delay line, and the third input is connected to its third input through a phase shifter, an indicator whose input is connected to the output of the first amplifier, and the local oscillator control input and The second amplifier is connected to the output of the low-pass filter, a notch filter, a limiter, a second low-pass filter, a switch, a peak detector, a second frequency detector, and a meter, which are input through the second frequency detector is connected to the output of the local oscillator and the second input of the traveling wave tube, the output of the first mixer through the second low-pass filter and the first switch of the bodies connected to the input of the first of the monitors, and the integrator connected to the input of a peak detector, the output of which is connected to the input of a low-pass filter, while a rejector filter is connected between the output of the second mixer and the input of the first intermediate frequency amplifier, and the limiter It is connected between the output of the first intermediate frequency amplifier and a second input of the first mixer. The drawing shows a structural electrical circuit of the proposed device. . 90 4 The device contains amplifiers 1 and 2 of intermediate frequency, mixers 3 and k, frequency detector 5 traveling wave tube (TWT), phase shifter 7, local oscillator 8, integrator 9, delay line 10, amplifiers 11 and 12, filters 13 and, 1 low pass, peak; detector 15 notch filter 1b, limiter 17, indicator 18, governor 19 local oscillator frequency, frequency detector 20, meter 21, switch 22. Index 23 denotes the generator to be tested. The operation of the device is as follows. When measuring the frequency modulation rate and the linearity of the modulation characteristics of FM generators (frequency deviations from the linear frequency modulation law), switch 22 is in the first position. The output linear-frequency-modulated signal of the generator 23 is fed through a delay line 10 with a delay time f on the TWT 6 with quadrature amplitude-4 nitrogen modulation output harmonic oscillation of the local oscillator 8. The nominal oscillation frequency of the local oscillator 8 F. is chosen so that it is significantly more than the expected otkponeniya instantaneous frequency of the investigated signals from the linear law of changing the magnitude of F nor the frequency in time. The magnitude of tens of megahertz on the delay line 10 of the delay is selected from the condition of providing the required range of measured values and is the tenth of twK seconds. The delayed signal, shifted in frequency by the value of F, is multiplied in the mixer k with the non-delayed signal being investigated by the 5th oscillator 23. At the output of the mixer 4, the combination components of the difference and total frequency as well as the low frequency component are formed. The difference frequency component fbp- (Fr + SC% (t) is allocated by amplifier 1. The low-frequency component is due to the fact that the quadrature amplitude-phase modulation does not provide full preparation of the unbiased component of the output signal of the TWT with the mixer k and the delayed and the delayed multiplication unbiased signal. It leads to a parasitic amplitude modulation of the useful difference component, and consequently, to a decrease in measurement accuracy. To reduce the parasitic amplitude modulation of the useful the signal to the input of amplifier 1 is fed through a notch filter 16 which suppresses an undesirable low-frequency component. Completely eliminating the parasitic amplitude modulation is carried out by the limiter 17 From the output of the limiter 17, the difference frequency signal is fed to the input of the mixer 3 to another input which is fed in harmonic heterodyne signal. 8. Amplifier 2 separates the signal of the second intermediate frequency FnP5 (t). The signal from the input of amplifier 2 is fed to the input of frequency detector 5 whose transition frequency is equal to This is the nominal frequency of the local oscillator 8 and is. With a negative sign of the speed of the Zastotnaya modulation (-g), the value of the second intermediate frequency Pn (and relative to the frequency 2fT-o decreases, and with a positive sign, the speed of the frequency modulation (+ j) increases. At that, the average for the duration of the pulse duration the frequency of the signal at the output of amplifier 2 with respect to 2Fro uniquely determines the magnitude of the speed of the frequency modulation of the signal of the generator 23; the inertial system of the AFC local oscillator 8, consisting of mixer 3, amplifier 2, frequency detector 5, integrator 9, peak vector 15, filter 13, amplifier 12 and controller 19 as well as frequency detector 20 and meter 21 automate the measurement of the magnitude and determination of the sign of the frequency modulation rate, and also simultaneously expand the range of frequency deviations from the linear frequency modulation law. The time constant of filter 13 is chosen to be significantly longer than the correlation time of deviations from the linear law of frequency modulation. Therefore, the magnitude and sign of the average frequency shift of the signal at the input of frequency detector 5 relative to but the frequencies characterizing the magnitude and sign of y are tracked by the homeland 8 and are measured by the frequency detector 20 with the meter 21. The transition 16 to the frequency of the detector 20 is selected. equal to 2fj (j, and the generator 21 is zero at the middle of the scale. This provides a direct measurement of the frequency modulation rate taking into account its sign. At the same time, the intrapulse frequency deviations from the linear law ((t) are measured by an indicator connected via switch 22 and amplifier 11 to the integrator output 9 Turning on the peak detector 15 provides stability regardless of the period of the radio pulses under study and improves the accuracy of measuring the frequency modulation rate J by reducing system errors in pauses between pulses. When measuring the frequency instabilities of the unmodulated signals, the switch 22 is in a different position. The output signal of the generator 23 is fed to the mixer k and the delay line 10 after multiplying the delayed and delayed signals shifted by the frequency F in the mixer C, as in the previously discussed case , at its output a difference frequency component is formed (fip / i -tAF (t), wheref (F) is the function, which in this case describes the deviation (fluctuation) of the frequency from its average constant value. This component is allocated by amplifier 1, is amplified, and through limiter 17 is fed to the input of mixer 3. A signal of a local oscillator 8 with an oscillation frequency Fj- is sent to another input of mixer 3. Since the frequencies of the signals at both inputs of the mixer 3 are the same, it operates in the phase detector mode, and its output voltage is proportional to the fluctuations of the frequency of the signal under study. This voltage is detected by the filter C and through the switch 22 and the amplifier 11 is fed to the indicator 18. The use of phase detection improves the accuracy of the measurement of the frequency fluctuations. Apparatus of the Invention A device for measuring the rate of change and frequency instability of a frequency-modulated oscillator signal, comprising a first intermediate frequency amplifier, a first mixer, one input of which is connected to a heterodyne output, and an output through a series-connected second intermediate frequency amplifier and a frequency detector connected to an integrator input, the second mixer, one input of which is connected to the output of the rotating generator, and the second input of the second mixer is connected to the output of the traveling lamp One input is connected to the output of the generator under test through a delay line, and the second input is connected to its third input via a phase shifter, an indicator whose input is connected to the output of the first amplifier, and the local oscillator control input through the successively included frequency controller and second amplifier connected to the output of the low-pass filter, which differs from the fact that, in order to improve the measurement accuracy, a notch filter, a limiter, a second low-pass filter, a switch, a peak detector, are introduced into it A frequency detector and a meter 18, whose input through the second frequency detector is connected to the output of the local oscillator and the second input of a traveling-wave tube, the output of the first mixer through the second low-pass filter and the first switch contact, Matel is connected to the input of the first of these amplifiers, and the integrator output is connected via the second contact of the switch to the peak detector input, the output of which is connected to the input of the low-pass filter, while the notch filter is connected between the output of the second mixer and the input of the first intermediate frequency amplifier, and the limiter is connected between the output of the first intermediate frequency amplifier and the second input of the first mixer. Sources of information taken into account in the examination 1. USSR author's certificate number 706795, class, G 01 R 27/06, 27.07.78.

2. USSR Author's Certificate No. 665278, cl. G 01 R 27/06, 06.12.76.